Thread: Does fixing driveline slack, fix jerky throttle?

Thanks Daz.
Is there ever much play in the front and rear diffs?

Originally Posted by Beery

Thanks Daz.
Is there ever much play in the front and rear diffs?

Yep, the rears often seem to be badly set up from factory. The fronts seem better (though I picked up a bunch of driveline slack when I snapped the planet gear shaft ).

Originally Posted by n plus one

Yep, the rears often seem to be badly set up from factory. The fronts seem better (though I picked up a bunch of driveline slack when I snapped the planet gear shaft ).

Maybe I should go and pay a diff specialist to set them up properly and then send the bill to Land Rover Australia.

Originally Posted by Beery

Maybe I should go and pay a diff specialist to set them up properly and then send the bill to Land Rover Australia.

In order of installation with comment on effect on perceived drive line slack as observed by clunkiness during gear changes and when getting on/off throttle:

- first I fitted Ashcroft ATBs to front and rear diffs (getting them set up by a skilled indie mech in process).

This did seem to reduce drive line clunks - a bit.

Not the prime purpose/benefit of ATBs but inherent design (no spider gears etc) means less slack inside diff centre. Proper setup of R&P also likely a factor in reduced clunks.

- second I installed BAS autobiography tune. This doesn't touch driveline mechanicals at all. But there was perceived reduction in clunkiness due to smoother, finer, throttle control

- thirdly I replaced drive flanges (4) with HD flanges from Ashcroft's. By far! This had the biggest impact with regards to removing perceived drive line slack and related clunks. Seriously thought my whole driveline had been replaced with a Toyota driveline. It actually felt like the term "taut" would not be hyperbole!

Cautions:
- the above comments are about a vehicle that had only 37k km on the clock by the time the flanges were done.
- there wasn't any visible wear on my axle splines. YMMV!
- if you left it longer so that axle splines were already worn, or had more axle spline wear than me at 37,000km then you won't see the same improvement I did
- if you have excessive slop in diffs, driveshaft splines, CVs, UJs, adapter shafts et al: then replacing drive flanges may not give YOU the stunning improvement I experienced
- I have only experienced the Ashcroft gear. Obviously good quality and also expensive! Only saying- maybe there are other brands as good. Maybe some options aren't as tight. So this too may be a variable that could mean you don't see the result I got.

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

Originally Posted by Beery

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

Yes definitely good low speed driveability. A combination of the autobiography tune and less driveline slack. I never get kangaroo hops or shunting.

My normal driving style, whether in a rush or just doddling along, has me take off from a standstill with no throttle. Once moving:
- if doddling I upshift around 2000rpm with minimal throttle openings. No clunks, shunting etc. very pleasurable.
- if in a rush, after a zero throttle take off from standstill, the moment the clutch fully up its throttle to the floor and upshift around 3500-4000rpm. Again no clunks or shunting.

Above works whether taking off in first or second gears.

In the infamous KL traffic jams I just pick a gear and idle along. Any gear from low range first to hi range 3rd ... No shunts etc.

I've mentioned this in other posts if you have a search but...

I do axle/drive flange change outs on Defender TDCi (pumas) with as little as 10,000KM on the clock because there is already free play in the splines, as 10K is just a trip round the block, it tells me the free play is there from factory.

Add to that the hardness of axles in a Defender TDCi (puma) is considerably less than previous Defender TD5 models (and I suspect as would replacement genuine axles for a TD5). On the rockwell hardness scale the best I've tested a puma axle at was 28HRC, compared to the lowest TD5 (original axle) at 37HRC. The axles out of a puma also readily machine, whereas the TD5 axles are tough and dont machine cleanly.

According to the ones that know diffs and axles, DANA say round 45HRC is the hardest you want an axle, after that its prone to breakage. So the original axles in the TD5 were prolly about right for hardness and toughness.

Once they have been replaced with such heavy duty brands as HTE, all is good, not only is the spline a very tight fit, with the screw on end cap, the outer splines become a easy service item to lube with grease.

Regards
Daz

Originally Posted by Beery

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

Just re-read your question. My last post waxed lyrical on irrelevant drive conditions and didn't say enough about the relevant one:
Low speed driveability in 1st & 2nd.

In traffic KL jams I can be in bumper to bumper slow speed crawls for up to 3hrs at the worst in daily commute. Good days it's only a 45min trip (35-40km).

As mentioned I usually pick a gear that I can idle along in to keep up and not be constantly stop start. At times the traffic moves a little faster so the job is to feed in a little throttle to close the gap, then back off to idle before having to touch the clutch to avoid nudging the car in front. So regardless the gear I am in its just modulating throttle between idle and 2000rpm for an hour or more.

Have used 1st and 2nd like that for extended periods. Sometimes upshifting from first to second and back again... (To match lane speed).

Really nice and smooth .. No issues.